I haven't built it yet so it's unverified but I've double checked it and I don't think there's any errors. I used a TL064 instead of a pair of TL062s because it made the layout a bit simpler, note that it's upside down compared to the other ICs. The layout might be a bit tight in places especially round the 10uF capacitors in the LFO, but the rest of it should be OK so long as you use sensible sized caps.If I get time I'll try and build it at the weekend.

I breadboarded this puppy with an LM13700 yesterday. It worked great for a couple of minutes, once I managed to keep all the leads from touching. It was definitely the most complicated thing I have attempted to breadboard. If I do something like that again I will put shrink wrap on any of the leads that risk crossing.

I did wind up replacing the TL072 with an NE5532. I don't know why, but making that change has made both this circuit and a Nurse Quacky I built last week work much better. Anyone have a theory?

Anyway, since I really liked what I heard while it was working, and I don't have a true vibrato circuit in my collection, I started doing the perf layout they recently posted this morning. I'll let you guys know how it goes once I finish. For the time being I am doing my best to emulate our buddy Freq Central...Uh, it just isn't coming out as neat as his work. But I am checking as I go, and so far so good.

Generally, yes. It has a low input impedance, and it loses its noise advantage when fed a high impedance signal. But, you know, lo-Z-in can sometimes be a good thing, in terms of taming harshness, etc. So if the 072 was too right or something was getting saturated in the circuit with it, the 5532 may be just the ticket. Did you try any other BJT-input opamps?

To tell the truth, breadboarding this created such a rats nest that my issues may have been caused more by that than the op amp. I am about 1/2 through perfing it up, and I am using sockets for the op amps, so I will be able to experiment more scientifically in a few days. I will post my results once I have them. I didn't try any other op amps, but I will once I have it put together, just out of curiosity.

But, it was a night and day difference with my Nurse Quacky. With the TL072 there was no envelope sweep at all. With the NE5532, it has a sweet resonant sweep. I got the idea from another post on here, so I am not alone in having that experience. I was surprised since I have read claims that the op amp doesn't make that much of a difference, but in certain circuits it definitely does.

Yes ive noticed op amps make certain circuits actually work, when some that should operate fine, don't. In Dr. Quack, the NE5532 did sound much different. However, in my MXR noise gate, it wouldn't work with a NE5532, any that I tried. Only with a TL072.

No kidding. I've been at it for a few hours, and I'm barely 1/2 done. And I am a pretty capable perf dude. But, since it is quite complicated, I am taking my time and doing continuity testing as I go to try to make sure I don't screw anything up. (Of course that would never happen!) Hopefully I'll have a working circuit by the end of the weekend. And hopefully you will as well once you get the parts.

El Heisendberg,

Interesting. I am definitely going to make sure I try several op amps with any build I am having problems trouble shooting. Luckily I have a little stock pile of the usual suspects now...

To get this far took me about 6 hours. I also triple check every connection cause this beast is going to be a pain to debug. That's how it's looking so far. It's my 3rd perf build, so let's hope it all works out

I don't know how you guys do it, but during my last build (professor tweed) i found it really helpful to have the layout loaded in photoshop and draw along while soldering. that way i have 2 or 3 layers on top of the layout where i draw in missing parts, substituted values or areas where there may be a problem later. really helpful to not get lost!

Hi there. just etched this, and was starting to populate it when I noticed what I think are indescrepencies between the layout and the schem.(u4=lm13600)in the layout on u4 pin 5 goes to a 1n5F cap, but in the schem it's pin 8 that goes to the 1n5Fin the layout on u4 pin 8 goes to a 1uF cap, but in the schem it's pin 9 that goes to the 1uFin the layout on u4 pins 10+12 go to a 22nF cap, but in the schem it's pins 5+7 that go to the 1uF

does it matter that they're different and has the layout been verified and tried? TIA

Finished and boxed up my Tri Vibe last night using Andre's layout. Sounds great! Thanks ROG/Andre. Very well thought out. With no need to adjust/tweek voltages to get it working properly makes this thing a breeze. Thanks guys.

+1. just finished populating mine with equivalent parts (lm324 and lm358) and it's awesome!just waiting for parts (right opamps and pot) and I'll houe htis up to take pride of place on my board. nice stuff ROG/Andre!

But, it was a night and day difference with my Nurse Quacky. With the TL072 there was no envelope sweep at all. With the NE5532, it has a sweet resonant sweep. I got the idea from another post on here, so I am not alone in having that experience. I was surprised since I have read claims that the op amp doesn't make that much of a difference, but in certain circuits it definitely does.

I'm not looking at the schematic of either effect right now (working, so I might as soon open porn as a schematic...), but the other big difference between a TL072 and an NE5532 besides input-Z and noise (sometimes) is z-out. The 5532 has a very low z-out, so much so that it can be used as an audio amp to drive, say, headphones. Most opamps can't even think of doing that. So, depending on what the load is that they are driving, that may be the difference in certain effects. The claims that you read concerning opamps not making much difference were probably about distortion effects, where the effect may be a function pretty much entirely of the circuit design, e.g. clipping diodes and e.q. elements, and the the opamp is pretty much there just to amplify within a very restricted part of its frequency and gain ranges, and where the in/out functions may be handled by other devices, such as the buffers in a Tubescreamer. But I doubt anyone with a clue would say that as a blanket statement.

Alright, scratch the previous info. I finally finished perfing this guy up, and I am having some strange issues. But, it is working best with the TL062's and the TL072 as spec'ed by ROG. But, it is doing some strange things. Instead of a nice steady pulse, I get a volume dip when I first hit the strings, then an uneven and very light vibrato effect. The only things I did differently are I used an LM1700 instead of the LM1600, I used a film cap for one of the 1uF caps since it is shown that way in the schematic, but not on the perf layout, and I figured a big fatty would add to the mojo, and I had to double up 2 electro caps to get the bidirectional one. It is shown that way in the schematic, but not on the perf layout. Oh, and I used a B type rate pot.

I did check the connections twice, and I am "pretty" confident I built it right. Does anybody have any ideas what to try? Should I try to get my hands on an LM1600?